The way potters and hobbyists traditionally pack electric kilns is the height of energy wastage. This 18x22 hexagonal kiln load of bowls is a good example. A traditional pack on the left does 24. The new method using 3D printed setters on the right does 36. The left firing contains only 5.3 kg of bowls with more than 60kg of furniture - each 220g bowl incurs 2700g (6 lb) of kiln furniture weight - seven times as much! This type of packing also leads to uneven firing and puts a heavy load on the electrical components. The bigger the kiln the greater the efficiency.

These light-weight stackable setters don't exist yet. But they soon will. I designed specifically for this bowl and printed samples using PLA. Sintered alumina, the ultimate material, has 3x density over PLA - so we can predict the weight at 160g. These setters allow free flow of air, even the foot of the bowl is exposed. They can be printed upside down with one pass of the nozzle for most of the geometry.

New uV hardened resins for dental applications are the inspiration for this idea. These resins and hardeners are commodity items online now, anyone with a clay 3D printer (or the ability to retrofit an existing PLA printer) can experiment with recipes (even of inexpensive refractory materials like kaolin, ball clay silica) and print these.

Simply put: Glaze misfit. The glaze is under compression and it is pushing outward. That compression was created as these terra cotta pieces cooled in the kiln. After the glaze solidified, somewhere above red heat, it became a glass and began to contract. The body, to which that glaze is attached by a glass bond, had its own higher rate of contraction. The glaze has some advantages in this battle. Its thick application gives it extra power to assert its thermal expansion. The body is over-fired and has become brittle. The unglazed outsides, incised designs and varying thickness provide points of weakness where cracks can start. The body resists the relentless force from inside but the odds were stacked against it and the pieces do not even make it out of the kiln. Of course, the glaze could be applied thinner, ware could be fired lower, it could have a more even cross-section and the outsides could be glazed. All will help, but increasing the thermal expansion of the glaze (by increasing KNaO at the expense of other fluxes), is one change that would fix this issue.

Lilly will take you step-by-step through the 3D design process of drawing a propeller. We tried many methods of doing this to finally arrive at a simple procedure that produces a flexible parametric design. Follow the full transcript as you watch. You can use the same process to create one in this or other CAD software. Our design has only nine steps yet is flexible enough to accomodate a different number of blades, changes in the blade shape, angle, thickness and size and different heights and diameters for the hub and hole. If you would like this 3D file in Fusion 360 format, it is available in the Files manager in your Insight-live.com account.

In the past, we have used Adobe Premiere for making videos. This video marks our transition to using KDenlive instead (please be patient with the rough edges until we learn this better). We are using it on Linux! It is amazing that a tool this powerful exists as free software (although they accept donations).

This assembly is the bottom half of a 3D printed 0.8mm wall thickness PLA mold. Until now I have super glued a thin disk onto the bottom, but a plaster pour again woke me up to how much outward pressure the heavy slurry exerts on molds tasked to contain it - the glue failed! This time I am doing a "belt and suspenders" solution. This bottom disk is much thicker and stronger and it is removable. These paper clamps hold it onto the flange and are recessed so the whole thing can sit flat-side down on the table.

Cutting-edge ceramic 3D printing is happening in dental! The focus is not primarily on the printers, attention is going into the paste. They are calling it "the resin" because acrylic resin is the likely medium. Pure alumina powder is being used (also pure silica). Imagine having a pure alumina tooth! What temperature does it take to fire these (and burn out the photopolymer network)? 1600C! They are achieving high percentages (likely 70%+) of the powder in an acrylic resin base and yet the slurry is very fluid (so it can be printed in a very narrow extrusion) and has minimal fired shrinkage. They are adding uV hardeners, this enables solidifying the material as soon as it leaves the printer nozzle. Data sheets specify exactly what uV wave length is needed. The key to the success of these efforts is meticulous lab work to perfect and adapt already established processes and materials. This material-centric lead could be adapted to so many other branches of ceramic fabrication and so many other materials could be made into resins. Another exciting area is investment casting. Thin ceramic shells are being printed and molten metal poured in to get shapes never before possible.

Traditional 50:50 kaolin:silica kiln wash can be a real bummer to use. It flakes, both on drying and after every firing. Pieces of it stick to the feet of ware (plucking). It is not refractory enough either. Shelves need cleaning and rewashing often. Three outside-the-box ideas make this a better recipe.

#1 No raw clay! Strangely, calcined kaolin is better than raw kaolin, it imparts multiple advantages.
#2 No silica. We use zircon or alumina instead, they are more refractory. And we use 80%, not 50%.
#3 We add CMC gum. It is the hardener, it enables a high specific gravity, imparts awesome brushing properties and slows down drying on cordierite and alumina shelves.

The low water requirement and slow drying make this behave more like paint. It can be applied by roller or brush. Coverage is much more even and it does not shrink and crack on drying. Normally the raw kaolin in 50:50 kiln wash suspends the slurry, makes it brushable and hardens it on drying. But CMC gum is way better for the latter two. It is so nice to be able to apply a thin layer of wash even on highly porous shelves (like these alumina ones we make ourselves). Unfortunately, we can't have everything - a down side of this recipe is settling (more information on the recipe page linked below). Fortunately, if used every few days it won't be a problem.

This is not available as a product, we just like it so much we made a label for it!

There is an undeniable appeal to the bright colors of many commercial glazes. While nobody is recommending abandoning them and going all-in on DIY, there is an appeal to having more control. If you are a potter, hobbyist or small manufacturer, consider: Do we want customers eating and drinking from these kinds of glazes? This type of ware is often crazed (runny glazes do that, especially on bodies they were not designed to fit). These are also prime candidates for leaching the high percentages of the heavy metals they contain. All those layers running and pooling on the insides can make pieces into glaze compression time bombs. For food surfaces, the glaze manufacturers want us using their recommended balanced, lightly colored products. Good news! These base recipes are also the easiest to make yourself. When did we get intimidated about mixing our own glazes anyway? No one has to go full mad scientist on DIY here. Research the common ingredients your supplier offers. Use recipes that pass a sanity test. Be a savvy consumer - these colored products are expensive and using them only on the outsides will cut your costs in half. Learn to add pigments to your base recipes and save even more. Then learn to make and use dipping glazes (not dripping glazes) and save time also.

Color like this, from commercial brushing glazes, has become so trendy that multiple problems associated with it are being ignored by potters and hobbyists at cone 6. First, crazing (this network of fine cracks): When people use dense-burning bodies, ware doesn't leak, so it is deemed to be OK. When ware is made using stoneware clays having higher porosities, and it leaks, the clay bodies are blamed. And the poor strength resulting from the crazing is also blamed on the clay. However, this potter has done two right things:
1. Using an iron-stained honey glaze on the inside (e.g. GA6-B). It does not, cannot, leach heavy metals. Many are misinterpreting the ASTM D-4236 label on glaze jars and using intense heavy metal colored glazes on food surfaces!
2. The honey glaze inside does not craze so the mug does not leak even though the body has a higher porosity than the supposed vitrification magic number of <0.5%.
The bottom line: Use glazes that don't craze, DIY ones if possible or necessary, don't use really bright colors on food surfaces.

Dec 6: I have been waiting since Dec 1 for someone to notice this was AI-generated! That happened today. I used an AI image for an obvious reason: A real piece would offend the maker. AI produced this on first try as representative of what's on social. Yes, AI photos are less authentic than DIY, so are pieces made in isolation of awareness of the critical design and safety flaws outlined here. This page gives part of the solution and links to full solutions.

Typical zero-boron high-temperature glazes will not soften in a 1500F decal firing. But low-temperature glazes will (especially those high in boron). Even middle-temperature ones, especially those having significant B2O3, can soften. G3806C (right), for example, is reactive and fluid, it certainly will. Even G2926B, which has high Al2O3 and SiO2, has tiny pits (because of the amount of B2O3 in contains). In serious cases, they can bubble like the mug on the right. What happened to this one? Steam. It was in use and had been absorbing water in the months since it was first glaze-fired at cone 03. The one on the left was not used, but it did have some time to absorb water from the air, it is showing tiny pits in the surface. Even if moisture is not present, on refire low fire bodies continue to generate gases of decomposition that affect glazes. Each decal manufacturer has a recommended firing temperature, that is for their decals, not your glaze.

This is a buff stoneware body, Plainsman M340. A L3954F black engobe was applied inside and upper outside at leather hard. The piece was fired at cone 6 using the PLC6DS schedule. The inside, totally clouded glaze is G2926B. Outside is GA6-B Alberta Slip amber transparent. Normally this inside glaze is crystal-clear on other bodies (and on this one without the black engobe). Clearly, the black stain in the engobe is generating tiny gas bubbles at the exact wrong time during the firing and the melt is unable to pass them. The outside glaze on on the same engobe, but the GA6-B glaze is demonstrating its ability to clear the micro-bubble clouding. It contains a lot of Alberta Slip, a material that is not finely ground like others. Particles across the range from 60-200 mesh are present, some of them appear to be acting as a fining agent to clear the bubbles.